Pour spouts are commonly used in eating and drinking establishments to provide for the controlled pouring of liquids, particularly alcohol, from bottles. Pour spouts are almost universally used in these locations since they relieve drink preparers free from constantly opening and closing bottles. Moreover, pour spouts allow the user to carefully measure, by time, the amount of liquid being dispensed.
A typical pour spout consists of conduit which is open at its lower end, with a smaller opening at its upper end. A gasket around the lower end of the conduit provides a seal between the bottle and the conduit to ensure that the only liquid which exits the bottle is that which exits through the small opening at the upper end of the spout. Many pour spouts also include a vent which allows air to enter the bottle to replace the exiting liwuid.
While pour spouts provide tremendous advantages over opening and closing each bottle, existing pour spouts present significant challenges. Of greatest importance, a pour spout provides an opening between the interior of the bottle and the atmosphere. While necessary for dispensing liquids, this opening allows organisms such as gnats and fruit flies to enter the bottles when they are not in use.
There have been simple measures employed to overcome this challenge. For example, some establishments simply place disposable cups over the pour spouts at the end of each evening. This solution is not only unattractive, but wasteful. More sifisticated attempts include providing pour spouts with removeable caps. While sound in theory, the caps are often lost, are hard to keep clean and do not seal the vent.